AB0654 PHOSPHATIDYLSERINE PROTHROMBIN COMPLEX ANTIBODIES UTILITY IN PLACENTAL INSUFFICIENCY MANAGEMENT. A CASE CONTROL STUDY IN A GENERAL OBSTETRIC CARE UNIT
Authors: A. Danza, F. Roca, V. Cambón-Boccardo, J. Viera, M. N. Sartre, R. San Martín, C. Montenegro, M. Rebella
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> The clinical utility of new antiphospholipid antibodies in cases of adverse obstetric outcomes is not well known<sup>1</sup>. <h3>Objectives</h3> To assess the performance of antibodies against the phosphatidylserine prothrombin complex (IgM and IgG), onwards "anti-PS/PT" in preeclampsia or foetal growth restriction. <h3>Methods</h3> A case control study was performed in a private maternal general care unit. Cases were patients with preeclampsia or foetal growth restriction developed before the 37<sup>th</sup> weeks of gestation. The full sample was calculated in 92 cases and 192 controls. Controls were patients who were hospitalized in the third trimester of gestation, with age +/- 5 years old respect to the controls, without known autoimmune diseases or history of adverse obstetric outcomes. All patients were studied with general laboratory, doppler, classical antiphospholipid antibodies and anti-PS/PT IgG and IgM. We present demographic characteristics and media comparisons which were performed with T test. Categorical variables were compared with Chi square test or Fisher test if applicable. The statistical significance was established in 5% (p&lt;0.05). Informed consent from the patients as well as approval from the institutional ethics committee were obtained. <h3>Results</h3> Two hundred and eighty-four pregnant women were included (192 controls and 92 cases). Demographic and clinical data of the groups are presented in Table 1. The median (IQR) anti-PS/PT IgM titles were 8 (8) MPL U/ml in cases and 9 (9) MPL U/ml in controls, p&gt;0,05. Regarding to anti-PS/PT IgG test, the median (IQR) titles were 5.5 (3) GPL U/ml in cases and 5 (5) GPL U/ml in controls, p&gt;0,05 <h3>Conclusion</h3> We did not find association between ant-PS/PT both IgG or IgM in cases of foetal growth restriction or preeclampsia. It is worth to note that this study was performed in a general care maternity, therefore, high risk cases were not included. Further analysis may show the utility of this biomarkers in obstetric adverse pregnancy outcomes management, particularly in other contexts as recurrent pregnancy loss, foetal death, or early severe preeclampsia<sup>1,2</sup>. <h3>References</h3> [1]Pleguezuelo DE, Cabrera-Marante O, Abad M, Rodriguez-Frias EA, Naranjo L, Vazquez A, et al. Anti-Phosphatidylserine/Prothrombin Antibodies in Healthy Women with Unexplained Recurrent Pregnancy Loss. J Clin Med. 2021;10(10):2094. [2]Gibbins KJ, Tebo AE, Nielsen SK, Branch DW. Antiphospholipid antibodies in women with severe preeclampsia and placental insufficiency: a case-control study. Lupus. 2018;27(12):1903-10. <h3>Disclosures</h3> Alvaro Danza has a grant from PANLAR to investigate in this area, he has no other disclosures to declare. <h3>Acknowledgements</h3> To the laboratory Biodiagnostico (Uruguay) which financed the reactives to perform the laboratory tests. <h3>Disclosure of Interests</h3> None declared